Riboflavin, also known as Vitamin B.sub.2, is a nutritional factor which occurs naturally in milk, eggs, malted barley, leafy vegetables, yeast, and many other sources. Minute amounts are present in all plant and animal cells. Riboflavin has long been identified as an important component of coenzymes required in the enzymatic oxidation of carbohydrates. Riboflavin has also been found to be a necessary growth factor for the dog and other mammals.
Riboflavin is made by all plants and many microorganisms but not by higher animals. Therefore, it is necessary for higher animals to satisfy riboflavin requirements through dietary intakes. The daily requirements for riboflavin have been established for humans and many agriculturally important animals. For example, the recommended daily allowance for a sedentary 70 kg man has been set by the National Research Council at 1.7 mg.
Dietary allowances have also been established for animals during pregnancy. For example, the currently recommended dietary level of riboflavin in swine feeds is 5.4 mg/day per pregnant pig (Nutrient Requirements of Domestic Animals, No. 2, 1979, Nutrient Requirements of Swine, 8th Revised Edition, National Academy of Sciences, National Research Council, Washington, D.C.). More recently, a dietary intake of 6.4 to 6.6 mg/day for pregnant pigs was recommended (Frank, G. R., J. M. Bahr, and R. A. Easter [1984] Journal of Animal Science 59:1567-1572).
Research leading to the National Research Council recommendations for dietary riboflavin consider the whole of gestation and the amount of dietary riboflavin necessary to allow pigs to have apparently normal pregnancies. However, these recommendations do not take into consideration that the animal's riboflavin requirements during pregnancy can vary during the course of gestation. It is well known that many hormonal and other biochemical changes occur during the course of pregnancy. These changes can trigger different nutritional needs on the part of the mother.
The subject invention provides a method for increasing the success of pregnancy in a variety of animals. The novel method takes into account the unique nutritional requirements of pregnant animals during a specific critical phase of pregnancy.